Simple ESP32/Arduino program for reading the SDS-011 output in continuous mode

pm-basic.ino

void setup() {
  Serial.begin(115200);

  Serial2.begin(9600, SERIAL_8N1, -1, -1, false);
}

void loop() {
  if (Serial2.available()) {
    byte pm_buf[10];
    Serial2.readBytes(pm_buf, 10);

    unsigned int pm_25_count = 0;
    pm_25_count = pm_buf[3] << 8;
    pm_25_count |= pm_buf[2];
    float pm_25 = (float) pm_25_count / 10.0f;

    unsigned int pm_10_count = 0;
    pm_10_count = pm_buf[5] << 8;
    pm_10_count |= pm_buf[4];
    float pm_10 = (float) pm_10_count / 10.f;

    Serial.printf("PM2.5 = %.4f; PM10 = %.4f\n", pm_25, pm_10);
  }
}